Template for edging lenses



Feb. 13, 1940. F. E. WOLF TEMPLATE FOR .EDGING LENSES Filed June 50,1938 gwwm iZiye ZZE. W09

Passed Feb. 13, 1940 UNITED STATES PATENT OFFICE 2,190,582 TEMPLATE FOBEDGING LENSES Fayette E. Wolf, Akron, Ohio Application June 30, 1938,Serial No. 216,812

3Claims.

This invention relates to-lens edging and pertains particularly toimprovements in gauges or template devices for facilitating the edgegrinding or edging of a lens blank according to an optometrists oroculists specifications.

It is well-known that in the practice of filling prescriptions forlenses, the dispensing optician takes from his stock lens blanks whichhave already been surface ground by the optical supply house to theproper correction as called for by the prescription. Since the axis ofthe lens in the human eye is usually several degrees from the truehorizontal and vertical axe and frequently the two eyes have a differentaxis, it is necessary to establish the angular deviation to correct theeyesight. Since the lens blank, which is to be edge ground, isconsiderably larger in diameter than the finished lens, the lens blankmust be rotated the required number of degrees from the true horizontaland vertical axes and the center of the finished or completed lenslocated by measuring in millimeters from the horizontal and verticalaxes of the unfinished blank, before edging. It is the practice incarrying out this edge grinding operation to lay out the grindingspecifications on the lens blank by means of lines marked on the glass.These lines frequently become washed off during the edging process andconsiderable time is required to re-locate the marks. After the centerof the finished lens has been determined on the blank and cut toapproximate shape and size, then the blank is placed in an edgingmachine which shapes the lens to the particular type of frame or to theshape desired.

The present invention has for its object to eliminate the necessity forlaying off the edging specifications upon the surface of the glass andthus avoid the objectionable features of this procedure, by providing atemplate disk of suitable material, preferably a disk of Cellophane orlike transparent substance, having laid ofl thereon standard markings inwater-proof ink and having an adhesive on one face whereby such disk ortemplate may be applied to the lens blank and retained thereon until theedge grinding operation is completed and the lens has been drilled forthe attachment of the usual nose pieces and temple bars.

A further object of the invention is to provide standard markings on theadhesive covered surface of such a template sticker or disk whichinclude a horizontal and vertical axis intersecting at the center of thetemplate with suitable millimeter-square markings on other portions ofthe template to facilitate the location of the proper edgingspecifications for bi-focal lenses and such other specifications as arerequired.

A still further object of the invention is to provide such templates ofstandard type which would apply to practically every ordinary job ofedging 5 lenses for the optical trade and it is intended that thesetemplate stickers shall be printed on rolls of tape material so thattemplates can be torn or cut off the roll and used as needed.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawing wherein:

Fig. 1 is a face view of a lens and my improved template appliedthereto. 1 Fig. 2 is a fragmentary section on the line 2-2 of Fig. 1,the section being enlarged.

Fig. 3 is a face view of a series of templates connected to each otherin the form of a continuous strip.

Referring to the drawing, in Fig. 1, I have illustrated a lens blank Ato one face of which is applied a disk ill of thin material, this diskbeing coated on one side with adhesive for effecting the secureattachment of the disk to the lens during the edging operation. Thisdisk is preferably formed of a transparent material such as Cellophanein which case the adhesive is also transparent, but it is to beunderstood that the invention contemplates the use of an opaque ma- 80terial if it is found that the same maybe effectively used in particularinstances. The adhesivecoated face of this disk is marked with avertical axis l2 and with a horizontal axis l3, these axes intersectingat the center of the lens blank. In Fig. 1, a template is shown whoselower portion on each side of the vertical axis 12 is laid out by aplurality of vertical and horizontal lines into millimeter-squaresdesignated generally M. In other words, this portion of the disk isdescribed with parallel lines extending at right angles to each otherand spaced on millimeter centers. At the lateral ends of the transverseline 13 there are vertical and horizontal lines designated generally l5for use as indexes for drill holes. It is to be understood that thesemarks l2, l3, II and I5 are made in water-proof ink and that theadhesive H is a water-proof adhesiv so that this template may be appliedto a lens blank without any danger of the template being washed away 60or the markings obscured or washed out.

In connection with the vertical and horizontal lines designated by thenumeral l 5, it is preferred that these be laid off in sixteenths of aninch rather than in millimeters.

While in Fig. 1, I have illustrated this template in the form of acircular disk, yet it is within the purview of my invention to printthese templates successively upon a continuous strip of transparentmaterial as shown in Fig. 8, so that this strip may be torn off atintervals, as shown in dotted lines in Fig. 3, to form the separatestickers for application to the lens. This strip I6 may be formed inrolls like adhesive tape so that the template can be torn off the rolland used as needed.

In using the strip form or the invention. the templates will be obtainedfor use as required by severing the strip in any suitable manner alongthe lines I! and the template may be directly applied to the lens or itmay be trimmed to roughly conform to the circular or other contour formof the lens which is to be ground. The markings of the strip may beeither upon the material of the strip or upon the adhesive thereof ifthe adhesive is suiiiciently transparent to show the markings throughafter the material has been applied to the lens. As previously stated,the actual grinding or the lens is done by the lens manufacturer and theopticians work consists in correcting the angular relationship necessaryand the decentration so that the axes of the lens will be properlyrelated to the axes of'the eyes when the lens are finally mounted insuitable frames or nose pieces. This decentration is the distancebetween the actual axes of the lens blank before edge grinding and theaxes of the finished lens as required by the prescription. It is in thisphase of the lay-out that the template lines are helpful to the opticianfor in the use of the template, the optician first locates the new axesof the lens or decentration line from the prescription and then placesthe vertical axes of the template at that point so that when the lens isedged, or edge ground, the vertical axis of the finished lens will becoincident with the vertical axis of the template.

Likewise the horizontal axis must be corrected according to theprescription and the segmental height, which refers to the location ofthe bi-focal lens if such is called for by the prescription. Thehorizontal line l3 and the lines M are used by the optician incorrecting the horizontal axis and segmental heights. In certain casesof very infrequent occurrence bi-fccal arrangements require a segmentallens above the horizontal axis in which case the markings l4 might beextended above the line l3. With this in view, it is contemplated alsoto provide templates having the markings M extended above the line l3although such an arrangement has not been illustrated.

The template after being properly located on the glass remains in placethrough the entire edging operation and until the lens is finished anddrilled. Because of the provision of waterproof markings on thetemplate, such markings cannot become smeared or shifted from theiroriginal position at any time in the process oi edging and the opticiancan determine at a glance whether or not the lens blank has shifted itsposition in the chuck oi the edging machine during such process.

when the lens blank is placed in a machine for marking, the angularrelationship to correct for the difference between the axis of the eyeand the true horizontal axis, the advantage of a transparent template isthat the lay-out man or sary for the operator to repeat the entireprocess of marking. Since the template markings in the present deviceare in millimeters, it is possible to tell at a glance where thedecentration line and segment height are. located as called for by theprescription. At the finish of the edging process and after the holeshave been drilled for the lens supports, the template may be removed anddiscarded and since these templates can be made at very low cost, theyneed only be used once.

What is claimed is:

l. A template for use in edge grinding single vision or bi-foca1 lenses,consisting of a sheet of thin transparent material coated on one facewith adhesive, the adhesive-coated face having perpendicularly relatedlines thereon designating a vertical axis and a horizontal axis for alens, the lower portion of the sheet at each side of the vertical axisbeing marked with millimetersquares.

2. A template for use in edge grinding single vision or bi-iocal lenses,consisting of a sheet of paper thin transparent material coated on oneface with adhesive, the adhesive-coated face having perpendicularlyrelated lines thereon designating a vertical axis and a horizontal axisfor a lens, the sheet at each side of the vertical axis and on one sideof the horizontal axis being marked with millimeter-squares, the ends ofthe horizontal axis being marked with squares of a definite size for usein indexing the drill holes for the lens supports.

3. A template for use in edge grinding single vision and bi-focallenses, consisting of a sheet of paper thin transparent cellulosicmaterial having an adhesive coating on one face, the adhesive-coatedface being marked with vertical and horizontal axis lines for a lens,the lower portion of the sheet on each side of the vertical axis linehaving crossing vertical and horizontal lines thereon definingmillimeter-squares and the ends of the horizontal axis line being markedwith squares of definite size as a means for index-

